In High school, we do not add time. We start and stop the clock at times prescribed in the NFHS rule book.
A bad throw-in goes the other way (a change of possession). No re-takes!
No substitution at any stoppage! Substitutions only at prescribed times and under certain circumstances prescribed in the NFHS rule book.
A cautioned player must leave the field, and may be replaced. If substituted for, may re-enter at next substitution opportunity. If not subbed for, re-enter at next substitution opportunity for that team.
A substitute becomes a player when beckoned on by the referee. He/she does not have to wait for the substituted player to leave the field. Beckon the substitute on immediately.
2022 Summary comparison NFHS - IFAB - NISOA (pdf)
Always mirror your partner’s Indirect Free Kick signal. Do not mirror a DFK signal.
Always make eye contact with partner before all re-starts!
Whistle all restarts after substitutions.
Bench-side official monitors substitutions with arm raised (mirrored by partner), eye contact when ready to re-start (count the players!), then drop arm and you or your partner whistles the restart.
Bench-side official keeps official time (backed up by partner’s watch).
On corner kicks, trail official should be at the 18!
On goal line or sideline calls, IF your partner looks to you for help, then help them out. Otherwise, call your own goal line and sideline, and trust your partner to call theirs. For a goal line call in the coffin corner, the lead official should look at partner before indicating restart.
Always face the field when making a throw-in direction signal.-never across your body.
On a foul, the trail official moves quickly up to the ball—no excuses!
On balls out of play, officials should glance at the halfway line to see if subs are waiting.